Study objectives: To evaluate exercise testing for the assessment of the extent of pulmonary disease in patients with sarcoidosis.
Design: Retrospective analysis of consecutive patients with sarcoidosis referred to the Pulmonary Physiology Laboratory between 1992 and 1997, who completed at least 6 min of progressive bicycle exercise. Resting and exercise pulmonary function measurements were compared to radiographic stage of disease.
Setting: Pulmonary Physiology Laboratory at Washington, DC, Veterans Affairs Medical Center.
Patients: Forty-eight outpatient veterans with biopsy specimen-proven sarcoidosis.
Results: Across all radiographic stages of sarcoidosis, total lung capacity, resting diffusing capacity, and exercise gas exchange measurements had a significant variance with radiographic stage. Across the early radiographic stage disease (stages 0 to 2), the change in alveolar-arterial oxygen pressure gradient between rest and exercise, normalized for oxygen uptake, was the most significant measurement in its variation with radiographic stage.
Conclusions: Changes in gas exchange with exercise may be the most sensitive physiologic measurements to assess the extent of disease in early radiographic stages of sarcoidosis.